PHILADELPHIA (CBS) – That epic Facebook rant you posted last night might have cleared your head, but it could also have a negative effect on anyone who sees it.

According to a new study published in the journal Plos One, moods are contagious on social media.

Researchers say they analyzed more than a billion Facebook updates from about a million English-speaking people between 2009 and 2012.

What they found is that negative emotions spread on social networks, spawning others to post pessimistic updates.

While previous research has focused on a similar concept, it mostly looked at people who were communicating face-to-face. This study, on the other hand, shows that the same applies to those communicating via social networks.

There is good news, though. Happy statuses are also contagious. When positive things were posted to social media, those upbeat feelings tended to spread as well.

While researchers note that the findings provide important information on human psychology, they also say that they could have implications for “public wellbeing.”

“To the extent that clinical or policy maneuvers increase the happiness of one person, they may have cascade effects on others in their social networks, thereby enhancing the efficacy and cost-effectiveness of the intervention, and these results suggest that such cascade effects may be promoted online,” the study’s authors conclude.

So the next time you feel like sending an angry tweet out into the world, take a deep breath and think about how far-reaching those 140 characters might actually be.